Re: How does pH affect the function of enzymes?

Dear Javed!

First of all review the concept of hydrogen bonds; it is a weak non- covalent bond between an electronegative atom and a hydrogen atom covalently bonded to another atom.

The protein molecules bend, coil and fold in different axes to make definite 3-dimensional shapes and they are held in these shapes by the hydrogen bonds. The specific 3D shape of a protein molecule is necessary for its proper functioning and as I told earlier the hydrogen bonds help maintain this 3D structure.

Enzymes are also proteins and so they also have 3D structures that are necessary for their proper activity. Increasing or decreasing the pH beyond the optimal range alters the hydrogen bonds, thus disturbing the 3D shape of the enzyme and making it inactive. Thus every enzyme has an optimal range of pH that is necessary to keep its hydrogen bonds appropriate for maintaining the particular 3D structure of the enzyme.

I hope I have cleared the matter to you. If you still have any confusion, feel free to contact me.

Faisal Nahri
MBBS student (2nd year)
Hamdard College of Medicine and Dentistry
Karachi